Patent GB-970112-A (GB)
Title: Coatings of cellulose crystallite aggregates
IPC: C09D101/02
Filed: 1960-08-29
Abstract: A structure at least a portion of the surface of which is a non-vitreous surface is coated with mechanically disintegrated cellulose crystallite aggregates having a particle size not exceeding 300 microns, said coating being deposited from a stable homogeneous, colloidal liquid suspension containing at least 0,1% by weight of said disintegrated aggregates having a particle size of up to 1 micron, the said aggregate constituting the acid-insoluble, crystalline residue of the acid hydrolysis of cellulose and being further characterized by having a "level-off DP" (degree of polymerization) of 15-375 anhydroglucose units, by the uniformity of the lengths of the constituent chains thereof, the constituent chains of each aggregate being separate and free of those in the neighbouring aggregates and by having a sharp X-ray diffraction pattern.  The surface to be coated may be wood, rubber, plaster walls, cork, paper regenerated cellulose sheets, food, iron, steel, synthetic and natural filaments, polyethylene, polypropylene and paper board.  The dispersions may also contain polyvinyl alcohol, carboxymethyl cellulose, methyl cellulose, dyes, pigments, oils and resins, e.g. catalysed urea-formaldehyde and melamine-formaldehyde resins.  The coatings on, e.g., paper may be dried by pressing the paper between heated plates.  The coatings may be transparent, lubricating or temporary.  Examples are given of coating and laminating regenerated cellulose sheet and paper, and of preparing copying-paper by coating with a cellulose aggregate gel containing linseed oil with or without a red dye.  The linseed oil may be replaced by alkyd, phenolic, modified alkyd or modified phenolic vehicles or resin-solvent combinations used in printing inks. Specifications 874,945 and 970,111 are referred to.ALSO:Food, e.g. frozen blocks of corn, peas or beans, chicken legs or breasts, ice-cream, butter, cheese, is preserved by coating with a mechanically disintegrated cellulose crystallite aggregates having a particle size not exceeding 300 microns, the coating being deposited from a stable, homogeneous, colloidal liquid suspension containing at least 0.1% by weight of said disintegrated aggregates having a particle size of up to 1 micron, the said aggregates constituting the acid-insoluble, crystalline residue of the acid hydrolysis of cellulose and being further characterized by having a "level-off DP" (degree of polymerization) of 15-375 anhydroglucose units, by the uniformity of the lengths of the constituent chains thereof, the constituent chains of each aggregate being separate and free of those in the neighbouring aggregates and having a sharp X-ray diffraction pattern.  The dispersions may also contain polyvinyl alcohol, carboxymethyl cellulose, methyl cellulose, dyes, pigments, oils and resins, e.g. catalysed urea-formaldehyde and melamineformaldehyde resins.  The coatings, being edible, may remain when the food is being prepared for consumption. Specifications 874,945 and 970,111 are referred to.ALSO:Surfaces are coated, impregnated or bonded together with mechanically disintegrated cellulose crystallite aggregates having a particle size not exceeding 300 microns, said aggregates being deposited from a stable homogeneous, colloidal liquid suspension containing at least 0.1% by weight of said disintegrated aggregates having a particle size of up to 1 micron, the said aggregate constituting the acid-insoluble, crystalline residue of the acid hydrolysis of cellulose and being further characterized by having a "level-off DP" (degree of polymerization) of 15 to 375 anhydroglucose units, by the uniformity of the lengths of the constituent chains thereof, the constituent chains of each aggregate being separate and free of those in the neighbouring aggregates and by having a sharp X-ray diffraction pattern.  The composition may be used to fill up the crevices in synthetic and natural filaments having a crenulated cross-section contour, to impregnate cork, to form paper laminates, and to coat paper to form pressure sensitive copying papers.  The dispersions may also contain polyvinyl alcohol, carboxymethyl cellulose, methyl cellulose, dyes, pigments oils and resins, e.g. catalysed urea-formaldehyde and melamine-formaldehyde resins.  The coatings on e.g. paper, may be dried by pressing the paper between heated plates.  The coatings may be transparent, lubricating or temporary.  Examples are given of coating and laminating regenerated cellulose sheet and paper, and of preparing copying-paper by coating with a cellulose aggregate gel containing linseed oil with or without a red dye.  The linseed oil may be replaced by alkyd, phenolic, modified alkyd or modified phenolic vehicles or resin-solvent combinations used in printing inks.  Specifications 874,945 and 970,111 are referred to.